During a field trip to the Peña-Corada Unit of the southernmost Esla region of the Cantabrian Mountains in 1927, the German stratigrapher Wilhelm Kegel sampled brachiopods and bivalves from a section in the Laoz valley near La Ercina. The stratigraphic position is believed to be part of the Nocedo Formation of Frasnian age. This fauna includes poorly preserved steinkerns of a near-shore bivalve fauna that was prepared for publication including labels and proposed names, but never published. The fauna represents only a very small and random part of the former community. But as information on Frasnian bivalves is scarce, the few specimens add important information on the distribution and palaeogeographic occurrence of near-shore, that is, Rhenish Facies bivalves within the south Laurussian – Rheic Ocean Realm. In the systematic part, seven bivalve taxa are described and discussed, most of which previously unknown from Palaeozoic Iberia and two of which are new. The revised list of bivalve taxa now includes members of the Eupteriomorphia, Palaeoheterodonta and Anomalodesmata: Leptodesma (Leptodesma) adaroi [Kegel] sp. nov., Pterinopectinella? sp., Aviculopecten? sp., Glossites sp., Eoschizodus? hispanicus [Kegel] sp. nov., Leptodomus? sp. and Edmondia? sp.